Along with improvement in performance of a microprocessor or the like stored in consumer electronic apparatuses and professional electronic apparatuses, the functions of the electronic apparatuses have dramatically improved. As a result, a conventional mechanical push button is insufficient as an input method for operating the electronic apparatuses. Instead, a combination of an operation screen and a push button, or a touch panel type of operation screen is frequently used. Such an operation screen has a multilayer configuration to orderly group the functions, thereby facilitating the operation which tends to be complicated.
Meanwhile, in the case where such an input operation using an operation screen is provided, a user with impaired vision may not be able to view the operation screen or may have difficulty viewing the operation screen. Therefore, an apparatus that allows such a user to perform an operation being assisted by sound for explaining each item, is used. However, given that a large number of candidate items are displayed on the screen and that there are a large number of multilayer screens, assistance by only sound information is not necessarily sufficient. That is, problems occur in which a user repeatedly returns to the same item or a user hardly recognizes which screen the user is operating, of the multiplayer screens.
In order to solve or relieve such problems, for example, Patent Literature 1 changes the kind or tone of sound produced when an operation button is pressed, depending on each layer, thereby facilitating identification of the current layer that a user is operating. For example, the tone of sound is changed in accordance with the depth of the layer.
In Patent Literature 2, if a user repeatedly returns to the same menu item being confused about the operation, a special explanation is outputted as sound when a cursor has moved to the menu item, whereby the user's operation is assisted. For each menu item, a counter counts the number of times the menu item is designated by the cursor. If the number of times exceeds a predetermined value, the special explanation is outputted.